Automatic telephone system



March 29 1927. 1,622,405

J. WICKS AUTOMATIC TELEPHONE SYSTEM Filed Jan. 23. 1922 4 Sheets-Sheet l 1Q w AJM@ - Imran Dr l Jahn Maks Z* 192 March 29, 7 J WICKS AUTOMATIC TELEPHONE SYSTEM Filed Jan. 23. 1922 4 Sheets-Sheet 2 Inman UI- Jnhn Mika n- Filed Jan. 23. 1922 4 Sheets-Sheet 5 Q H( gw MQ Q s 5W' N @x 4] N \1l 4 1,622,405 March 29, 1927 J, w| c KS AUTOMATIC TELEPHONE SYSTEM lMarch 29, 1927.

J. WCKS AUTOMATIC TELEPHONE SYSTEM -Sheet Filed Jan 23 1Q?? M my 1| Juhu Hunks M- FlT-L' #Ew QQ J R M Patented Mar. 29, 1927.

UNITED STATES 1,622,405 PATENT OFFICE.

JOHN WICKS, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO AUTO- MATIC ELECTRIC INC., OF CHICAGO, ILLINOIS, A CORPORATION 0F DELAWARE.

AUTOMATIC TELEPHONE SYSTEM.

Original application filed March 8, 1920, Serial No. 364,069. Divided and this application filed January 23, 1922. Serial- No. 531,076.

My invention relates in general to automatic telephone systems but .is concerned more particularly with methods of handling long distance calls in such systems, as is disclosed in my prior application, Serial Number 364,069, March 8, 1920, of which this application is a division.

The object of the invention, in general is to provide a new and improved toll service trunking system for connecting local subscribers in automatic exchanges with long distance lines, either as calling or called subscribers.

Toll service trunking systems of the above character have been known before, and I wish to refer to U. S. Patent #1,315,444, issued to me on Sept. 9, 1919, which shows and fully describes a modern system of toll service trunks, and also to my pending applications, Serial Numbers 155,640, March 19, 1917, and 346,323, Dec. 20, 1919, which show various improvements in such systems. lhe present application is directed to the same general objects, and includes a number of improvements,vone of which lies in the provision of circuit arrangements in a toll service trunking system, whereby a toll operator can successfully handle calls from subscribers stations which are equipped with the well known coin collecting devices which are commonly known as Gray paystations, shown and described in the U. S. Patent to Forsberg, #1,043,219, Nov. 5, 1912. I have devised complete circuits which enable the toll opeiator to collect or refund deposited coinsas desired, and which at the same time give the operator lamp supervision over the collecting and refunding operations according .tostandard practice.

In addition to the above I have found it advisable to make many circuit changes, and have made numerous other improvements not especially connected with the paystation feature, all of which will be pointed out and fully described in the detailed specification which follows, reference being had to the accompanying drawings forming a part thereof.

In the drawings, comprising Figs. 1, 2, 3, and 4, I have shown by means of the usual circuit diagrams the apparatus and circuit connections necessary to establish a complete connection in my improved toll service trunking system. In View of the well known character of the apparatus involvedvcircuit improvements in which the real invention lies, and which will now be proceeded with.

For this purpose it will be assumed that the subscriber at substation A, Fig. 4, has placed a long distance call with a toll recording operator and that the ticket containing the usual data concerning the desired connection has been forwarded to the toll operator having the cord circuit O, Fig. 1, for completion. Having extended a connection to the desired distant exchange over one of her toll lines, as for example the toll line which terminates in jack J, Fig. 1, and having ordered the proper local line to be connected up in that exchange, the toll operator will next proceed to call the subscriber at substation A by` way of the toll service trunking system. Observing that the toll servicey trunk terminating in jack J is idle, as indicated by the Iunlighted condition of the busy lamp L, the operator will insert the calling plug of cord circuit O in the said jack J', the combination ringing and listening key K being thrown to listening position. Upon the insertion of the plug in the jack J a circuitis completed for relay 20 as follows: ground at G', winding of relay 20, sleeve of jack J', sleeve of plug, contact springs of key K, the impulse springs of the calling device S, and the resistance 4 tol battery. Upon the closure of the alcove circuit` relay 20 is energized and completes a circuit for the slow acting relay 21, which upon energizing in turn connects ground Gr2 to the release trunk conductor 58 extending to the toll selector E. A branch of this conductor extends to the busy lamp L3 and its multiples in other positions (not shown), and the lamps are lighted to indicate that the trunk line associated therewith is busy. When relay 20 energizes it also closes a control or operating circuit for the toll selector E which may be traced as follows: ground at G3, Winding of the line relay 51, resting contact of armature 63 and the said armature, armature 30 and its resting contact, ar-

tor grounded locally while the switch is being operated.

The toll operator will now operate her calling device S in accordance with the telephone number of the subscriber at substation A. lVhen the calling device dial is operated in accordance with the first digit of the number, a series of interruptions is produced in the circuit of the relay 20. Responsive to these interruptions in its circuit, relay 20 decnergizes momentarily a corresponding number of' times, and produces a series of interruptions in the circuit of the line relay 51 of the toll selector E. The line relay 51 is therefore deenergized a plurality of times corresponding to the digit called, and at each deenergization sends a current impulse through the slow acting series relay 53 and the vertical magnet 56 to battery. By the operation of the vertical magnet the switch shaft is raised step by step until the wipers 7 0-73, inclusive, stand opposite the horizontal level of bank contacts which are terminals of trunk lines leading to the desired thousand group. The slow acting series relay 53 is energized in series with the vertical magnet, maintaining its armature continuously attracted during the vertical operation of the switch, and closes a circuit for the stepping relay 54. The stepping relay 54 is therefore energized, and-when the off normal springs are shifted at the first upward movement of the switch shaft, establishes a locking circuit for itself by way of the oil' normal springs 59. At the end of the vertical movement of the switch the slow acting relay 53 is deenergized and completes a circuit for the rotary magnet 57 which extends from the grounded conductor 58 by way of the armature of stepping relay 54 and its working contact, the olf normal l springs 59, and contact springs controlled by the armature of relay 53 to the said rotary maonet 57. The rotary magnet is according y energized and advances the wipers -73, inclusive, into engagement with the first set of bank contacts in the level opposite which they were raised. Near the end of the stroke the rotarynragnet breaks its own circuit and also the circuit of the stepping relay 54, which is accordingly deener gized to open the circuit of the rotary magnet at another point. Both the rotary magnet 57 and the stepping relay 54 having deenergized, the operation now depends upon whether the test contact with which the test wiper 71 is in engagement is busy or is not busy. It this test contact is busy, it will have a ground potential upon it and a circuit will be established which extends by way of the said test wiper, conductor 65, lower armature of relay 50 and its resting contact, ott normal springs 59, and the winding of the stepping relay 54 to battery. By current flow over the' above circuit the stepping relay 54 is again energized and again closes the circuit of the rotary magnet 57 which in turn operates to advance the switch wipers into engagement with the next set of bank contacts. This operation continues as long as the test wiper 71 continues to engage grounded test contacts. As soon as the first non-grounded test contact is reached, which we will assume to be the test contact 75 associated with the trunk line comprising conductors 78, 79, and 80, the stepping relay 54 will not again be energized, and the rotary movement ot' the switch will cease. The switch-ing, relay 50, which heretofore has been short circuited, is no'w energized over the following circuit: grounded conductor 58, winding of the switching relay 50, off normal springs 59 and the winding of the stepping relay 54 to battery. Relay 50 is of such high resistance that the stepping re- =lay 54 is not energized. Upon energizing,

relay 50 connects the grounded conductor 58 to the tet wiper 71 in order to make the multiples of test contact 75 busy to other switches, opens the circuit of the release magnet 55, and at its armature 63, disconnects the control or operating circuit from the line relay 51 and extends it by way of the working contact of the said armature 63, conductor 66, wiper 7 2, bank contact 76, conductor 79, Winding of the marginal relay 109 of the repeater D, Fig. 2, armature 137 and its resting contact, and the winding of the line relay 104 to ground. Upon the extension of the control circuit as above described, the line relay 104 is energized and completes a circuit for the slow acting release relay 105. Upon energizing, relay 105 connects ground at its armature 129 to the release trunk conductor 144 thereby closing a circuit for relay 102 which upon attracting its armatures 120-121 closes the upper and lower talking circuit conductors through the repeater. It should be mentioned that the relay 109, which is included in the circuit of the line relay 104, is shnnted by a noninductive resistance and is marginally adjusted so that it will not energize at the present time.

The talking strands of the operalor`s cord circuit have now been extended by way of the springs of jack J', the conductors 61 and 62, wipers 70 and 73, bank contacts 74` and 77, conductors 78 and 80, left hand winding of the repeating coil R, armatures 116 and 117 of relay 100 and their respective resting contacts, and resistances 112 and 114 tobattery and ground, respectively. It follows that the bridged supervisory relay 3 at the cord circuit O will be energized to light the supervisory lamp L. It may be mentioned at this .time that after the relays 51 and 52' of thetoll selector E have deenergized, the switching, relay 50 is maintained energized over the release trunk conductor 58 coming from the armature 25 of the slow acting relay 21, which relay is associated with the jack J. This method of establishing a holding circuit by extending the ground forwardy instead of backward is contrary to the usual practice, but is adopted here because in certain .circumstances the' 160 and its resting contact, and thewinding of tne line relay 151 -to battery, Upon the closure of the above" circuit'the line relay f 151' isenergized, and completes a circuit `for. the slow-acting release relayf152 in theusual manner. Upon energizing, relay152 grounds.

bridgefrelay' 200, and the upper Windthe 'release trunk conductor locally Vatits4 upper armature, and at its lowerjigarmature prepares thecircuits of the selector-folgrthe vertical operationthereof.v '-Thejyto ator may now operate the dial 'of .here

ing device S in accordance' withQtlief second'. digit in the number of subscriber at"'substa tion A. The interruptions produced by this operation are repeated byrelayf20 andby the line, relay 104 of the repeater D, and

cause a series of deenergiz'ations oftheline.v

relay 151 of the selectorF.- The'tollsecond selector Fis very similar to thel sel`e`c'to'i 'E i and Aits operation thereforewill not bel-cle'-l scribed in detail. Itwill be,suiiicienttosay;` that .ther deenergizations -of the line` relay` 151 bring about the operation ofthe'fyefrtic'al,-

magnet i 156- through Athelfimediuni"ofwliich `site Vvthe horizontal level-'lofib'airklconta' which Varej terminals of "trunk f llnesfleadm 154 byway of the off normal vContact springs 159. The stepping'relay locks itself as fdt the switch shaft is raised-step by stepxunti t the- *Wiperfs* 1711+173, inclusive; ,Stand'eppo suuieffl to'be'located in the banks of one of -Jtheregular selectors referred to, and the ground. potential upon conductor 305, and' ithe'testfcontact 302 and its multiples, renusual and prepares a circuit for the rotary magnet 157. At -the end of the vertical movement of the switch, the slow acting relay 153 is deenergized and the switch wipers are rotated in Search ofan idle trunk line by means of the rotary magnet 157, which is controlled by the stepping relay 154 and the test wiper 171. When an idle trunk line is reached, which we will assume to be the trunk line comprising conductors 178-181, inclusive, the rotation of the switch will cease, leaving the wipers 170-173, inclusive, in engagement with bank contacts 174-177, inclusive. The switching relay 150 is now energized and at its armatures 161 and 163 connects the talking conductors 141 and 145 with the line wipers 170 and 173,'

respectively. Relay 150 also extends conductors 142 and 143'by way of its armatures 162 and 160, wipers 171 and 172, and bank contacts 175 and 176 to conductors 179 and 180. The conductor 143 is included in the control circuit of the toll selector F, and when it is extended as above mentioned, the line relay 151 and the release relay 152 of the selector are of course deenergized, the selector being maintained in operated position' by the continued ener- ,gization ,of the switching relay 150, which is supplied with ground over the conductor 144 coming from the repeater D. I Thevswitch-control circuit having been extended, as. above stated, to the conductor ,180,1 itfmay be further traced by way of the said'onductor 180, the upper winding of thef-relay204-xof the combination connector ig',14acontact'vspringsA controlled by the f `tliejline relay 201 `to battery. Upon ysionI ofthe control circuit o ver the patli",`"'the line ,relay 201 is energized completes` a circuit for the slow acting releaserlrelay'202, which at its armature 216 *prepare's the connector for vertical operatio vinthel usual manner. 'At its upper armature rel'ay 1202'connects ground G8 with the release.;trunkconductor 305, which conducftor" ends to and ismultipled in the banks of1the-fsecondfselectors of the regular exchange trunking system which have access tothefcoinbinaton,toll and regular connectorf-HggjfConductor l305 is the release trunk C On uctor ofthe trunk line comprising con- 4'04;,Q3()5.and 306,v which terminate bank.- .contacts'301, 302, and 303 respec- ,',-'Fig.-3. `lThese bank contacts are as- $305,vwinding of relay 207, left hand winding ofthe induction coil R2, conductor 179.

soy

bank Contact 175, wiper 171, armature 162 and its working contact, conductor 142, armature 128 and its working contact, lower winding of the induction coil R1, armature 119 and its resting contact, and the resistance 111 to battery. By current flow over the above circuit the relay 207 is energized and at its armatures 236 and 237 prepared circuits for the ring cut ott relay 205 which will be explained later. Relay 207 also closes a circuit for the switching relay 204 by means of its armature 238, and the latter relay upon energizing produces a number of circuit changes in the connector which are brought about for the purpose of enabling it to function as a toll connector rather than as a regular connector. These circuit changes include the opening of the permanent locking circuit of the ring cut off relay 205 at armature 225, the shifting of the locking circuit of the busy test relay 206 at armature 224, the disconnection of the regular trunk line conductors 304 and 306 at armatures 223 and 226, and the preparation of a busy signalling circuit for the toll operator at armature 223. These circuit changes and the results effected thereby will be mentioned more in detail hereinafter. Before proceeding.,r further with the explanation a few more details concerning relays 207 and 204 may be inserted with benct. Relay 207 is of relatively low resistance, and the circuit traced through its winding from the grounded conductor 305 to the conductor 179 and test contact 175, places a potential upon the said test contact 175 and its multiples which is sufficiently near to ground potential to render the connector H busy to the toll second selectors. With regard to relay 204. the upper winding of this relay, which is included in the circuit of line relay 201, is of low resistance and is not necessarily strong enough to energize the relay by itself, but is strong enough to hold the said relay in operated position after it has been completely operated by the closure of the circuit through its lower winding. In order to reduce the impedance of the upper winding so as not to interfere with o rating impulses transmitted to the line relay 201, the relay 204 is provided with a copper slug as indicated in the drawing.

The connector H is now ready to be operated under the control of the calling device S, when the dial is actuated in accord: ance with the next digit in the number of the subscriber at the substation A. A series of interruptions is produced as before, which are repeated by the relays 20 and 104 to bring about a series of deenergizations of the line relay 201. At each deenergization the line relay transmits a current impulse through the vertical magnet 210 over the following circuit: ground at G7, armature 215 and its resting contact, armature 216 and its working contact, off normal springs 222 and 220, winding of the slow acting series relay 203, and winding of the vertical magnet 210 to battery. This is the circuit over which the first impulse is transmitted. At the lirst upward step of the switch shaft, however, theoif normal springs are shifted, and the circuit`v extends from the working contact of armature 216 by way of otl' normal springs 222 and 221, armature 217 and its working contact, (relay 203 being now energized), winding of the relay 203, and the winding of the vertical magnet 210 to battery. By the operation of the vertical magnet the switch shaft is raised sfep by step until the wipers 270-272, inclusive, Stand opposite the level of bank contacts in which the line of Substa ion A is terminated. The slow acting relay 203 which is energized inserics with the vertical magnet, maintains its armature attracted throughout the vertical opcratlon of the switch.l When this relay energizcs at the beginning of the vertical n'iovement it closes the following circuit for the ring cut-off relay 205: ground at G". armature 218 and its working contact, armature 219 and its working contact, working contact of armature 237 and the said armature, and the lower winding of the ring cut otf'relay 205 to battery. Upon energizing, relay 205 opens contacts included in a` later established signalling circuit at its arn'iatures 227 and 229, and at its armature 228 establishes a locking circuit for itselt` as follows: grounded conductor 305', working contact of armature 228 and the said armature, armature 236 and its working contact, and the lower winding of relay 205 to battery. At the end of the vertical movement of the switch, the slow acting relay 203 deenergizes and prepares the connector for operation in its rotary movement.

The toll operator may now operate the dial of the calling device S in accordance with the final digit in the number of the subscriber at substation A. The interruptions produced are repeated as before through the'inediuin of relays 2O and 104, and cause another series of decnergizations of the line relay 201 of the connector H. At each deenergization the line relay now sends a current impulse through the rotary magnet 212 over the following path: ground at GT, armature 215 and its resting Contact, arma ture 216 and its working contact, olf normal springs and 221, armature 217 and its resting contact, resti-ng contact of armature 233 and the said armature, armature 246 and its resting Contact, and the winding of the rotary magnet 212 to battery. In response to these impulses the rotary magnet operates to rotate the wipers 270-272, inclusive, into engagement with the particular set of bank contacts in which the line of substation A terminates, these bank contacts being the contacts indicated inthe drawin r by the reference characters 273, 274, an 275. The slow acting relay 208 is energized in parallel with the'rotary magnet and retains its armatures attracted throughout the rotary movement of the switch. At its armature 239, relav 208 connects the test wiper 271 to the Winding ofthe busy test relay 206, and at its armature 240 relay 208 closes a shunt around armature 233 of relay 206 and its resting contact to guard againstthe possi bility of the said relay being momentarily energized While the test Wiper 271 is passing over busy test contacts. In order to afford an opportunity to explain the operation. of the busy test circuits it will be assumed that when the line of substation A is called at this time it is busy. In such case the test contact 274 will be grounded and when the test wiper 271 makes connection with the said test contact, the lest relay 206 will be energized, the circuit being traceable as follows: grounded test contact 274, test wiper 271, contact springs controlled by armature 244, of relay 209, armature 239 and its working contact, armature 243 and its resting contact, and the winding of the test relay 206 to battery. The test relay is energized over the above circuit and when the slow acting relay 208 deenergizes at the end of the rotary movement of the switch, the test relay becomes locked up bygmeans of the following circuit: grounded test contact 274, test wiper 271, working contact of armature 224 and the said armature, working contact of armature 230 and the said armature, contact springs controlled by armature 239 of relay 208, armature 243 and its resting contact,

and the winding of the test relay 206 to battery.

The various circuit changes effected by the operation of the test relay will now be briefly pointed out. Its locking circuit which is closed at armature 230 has just been explained.` At armature 231 the circuit of the switching relay 209 is opened, at armature 232 a shunt is connected around the armature 236 of relay 207 and its working contact in order to prevent accidental deenergization of the ring cut oli relay 205 (by movement of ringing key at the operators cord circuit), at armature 233 the circuit of the rotary magnet 212 is opened in order to prevent the switch wipers from being rotated oil the contacts of the called line, and at armature 235 alead from the busy signalling machine Q, is connected to the lower line conductor 181., The conductor 181 extends back through the selector F to the lower right hand winding of the re-4 peating coil R, andl it follows that the toll operator will be given an audible busy sig nal indicating to her that the called line is busy. This lbus similar to metho in common use, and will signalling operation is.

be understood .without further explanation. The operator is also given a visual flash busy signal in the following manner: When the test relay 206 is energized a circuit is completed which extends from ground by way of the interrupter I, switch P, resistance 269, resting -contact of armature 241 and the said armature, armature 234 and its working contact, and the working contact of armature 223 and the said armature to the upper line conductor 178, whence the circuit may be traced over the upper conductor of the talking circuit back to the upper right hand winding of the repeating coil R, and through this winding andv the winding of the battery feed relay 100 to battery. The circuit above traced is intermittently opened and closed by means of the interrupter I, and it follows that the relay 100 will be intermittently energized and deenergized. By this operation of the relay 100, battery and ground are intermittently disconnected from the trunk conductors 78 and 80, causing an intermittent operation of the supervisory relay 3 at the operators cord circuit. This gives the operator a visual busy signal. If it is desired to depend solely 'on the audible busy signal, the switch P may be set so that the interrupter I is cut out of the circuit, thereby providing for the ermanent extinguishing 'of the supervisory amp when a bus line is called, and in the case of the cor circuit `vO, shown herein, this might well be done because the calling device key and the listening key are comblned in one structure, and when the operator finishes dialling a number her head set is necessarily cut across the trunk circuit in readiness to receive an audible busy signal. However, certain types of cord circuits have separate calling device keys so that the operators can dial numbers and set up connections while talking on other circuits and in such cases the busy Hash signal is of great-utility; and it is of considerable value even in the present system, because itis a constant reminder to the operator that she has a connection upon a busy line, and thus removes the possibility of her confusing the" connection with an answered call.

To proceed with the explanation, the toll operator will now restore her listening key K and may proceed to work on other connections while waiting for the line of substation A to become idle, first, however, operating the cut o key K in her cord circuit in order to prevent the busy tone from passing lout over the toll line. Or she may withdraw the plug from the jack J if she prefers. As soon as the line of substation A becomes idleground potential is removed from the test contact 274 and the locking circuit of the Ytest relay 206 is broken. The test relay therefore deenergizes, disconnects the busy signalling machinei Q, opens the busy flash signallin circuit, and establishes a circuit for the swltching relay 209 which may be tracedy as follows: grounded conductor 305', armature 231 and its resting contact, upper winding of the switching rclay 209, resting contact of armature 239 and the said armature, contact springs controlled by armature 244, test wiper 271, test contact 274, winding of the switching relay 317 of the individual line switch C; and the'wnding of the stepping magnet 318 to the common bus-bar 319, whence it extends by way of the low resistance secondary winding of the tone test signalling machine Q to battery. Upon the closure of the above circuit relays 209 and 317 are energized in series, and the latter relay is operated to disconnect the line conductors 320 and 321 from their normal connections in the line switch. Relay 317 is not completely operated because of the fact that the line relay of the line switch has not been energized and does `not connect the line conductors with the wipers of the line switch. In the connector H, the relay 209, upon energizing, opens the circuit of the rotary magnet 212 at armature 246, establishes a locking circuit for itself at armature 245, connects ground Gr11 to the test wiper 271 at armature 244, thus closing the circuit of the switching relay 317 of the line switch over a new path excluding the upper winding of relay 209 which was formerly included in the circuit, and at armatures 242 and 247 closes the talking circuit through to the line wipers 270 and 272.

'lhe connection has now been established with the line of substation A. When the busy test. relay 206 is deenergized and the connector cuts through on to the called line as described in the proceeding paragraph, the supervisory lamp L at the operators cord circuit stops flashing and is lighted continuously, thus indicating to the operator that the busy line with which that particular cord circuit is connected has become idle and that the connection thereto has been completed. The operator will now go in on the line with her listening key in order to listen for the tone test which is associated with the paystatien lines. The stepping magnets in the individual line switches of the paystation lines are supplied with battery through the low resistance secondary Winding of the tone test transformer, indicated in Fig. 4, by the reference character Q. Apparatus of this kind is well known and has been used before to indicate to an operator the character of a calling line, a system of this character being shown in the U. S. patent to Bernard D. Willis, No. 1,281,112, Oct. 8. 1918. I believe, however, that this is the first time a circuit arrangement has been provided for giving the toll operator; a distinctive tone test through al toll service trunkm system to indicate the character of a calle means of induction coil R2, induction coll R', and repeating coil R. The circuits are not especially ditiicult, and need l not be traced out in detail. To proceed, the operator is advised by the distinctive tone in her receiver that the subscriber who she has called over her toll service trunks and who desired `a toll connection is a paystaton subscriber and she will know therefore that the call will'have to be paid for in cash and will not be charged. i

The next operation is to-ring the subscriber at substation A. nor this purpose the operator throws the key K momentarily to ringing position, thereby projecting ringlng eurrent out over the trunk line with which the cord circuit O is connected, to operate the alternating current relay 101 at repeater D. Upon attracting its armature 119, relay 101 breaks the previously described circuit of the relay 207 at the connector H. Relay 207 accordingly deenergizes and at its armature 236 breaks the lockingcireuit of the ring eut off relay 205. Relay 205 then deenergizes and at its armatures 227 and 229 opens the talking conductors and establishes the usual signalling circuit which includes the ringing current generator Gen. and its own upper winding. There is no especial novelty in the signalling circuit itself, and the bell at substation A will be rung automatically as long as the receiver remains on the hook. During the ringing operation the operator is given the well known ringing current induction, provided of course that she is listening on the line, to notify her that line. 'As disclosed here- 1n, the tone is transmitted to the operator b i the ringing is proceeding satisfactorily.`

This is accomplished by means of the inductive path which extends from armature 247 of relay 209 by way of the low capacity condenser 299 to the resting contact of armature 235 of relay 206. Condenser 299 is of very low capacity, preferably about .005 microfarads, and permits just enough ringing current to leak back in the direction of the operator to give her an easily distinguished signal.

When the subscriber at substation A re'- moves his receiver in response to the ringing of his bell the ring cut off relay 205 will he operated by current from the exchange hat tery in series with the ringing current generator Gen. or by current from the exchange battery in series with booster battery associated with the generator, and upon attracting its armature 228 will re-establish its former locking circuit, the operator having restored her key by this time to permit the energization of relay 207. The ring cut olf relay also disconnects its own upper winding and the ringing apparatus at its armatures 227 and 229, respectively, and closes the talking conductors at these same armatures. The transmitter at substation A is now supplied with talking battery through the winding of the battery feed relay 100 at the repeater D. This circuit will not be traced in detail but it will be observed that the lower line conductor extends uninterruptedly back through the connector H and the selector F, to the lower right hand winding of the re-v peating coil R, whence it extends through the resistance 113 to ground, while the upper line conductor 320 extends back through the connector H and the selector F to the upper right hand winding of the repeating coil R, from which point it may'be traced through the said winding and through the winding of the relay 100 to battery. Relay 100 is energized by current flow through the transmitter at substation A, and` upon operating its armatures 116 and 117 breaks the circuit of the supervisory relay 3 at the cord circuit', and causes this relay to deenergize to extinguish the supervisory lamp L.

The operator will now come in on the line again by throwing her key K to listening position, and after ascertaining that the proper person is at the telephone will request such person to deposit the correct coin or coins to pay for his connection. When the coins are deposited the operator is given an audible signal over the telephone circuit in the usual manner so that she will know that the right coins have been deposited, and also the polarized magnet of the paystation is connected to the linein order that the operator may thereafter either collect or refund the coins.

Everything is now in readiness for conversation to begin, at least so far as the connection to the party at substation A is con; cerned. Assuming that the desired party has been obtained in the distant exchange, the operator will now complete the connection at her cord circuit and the connected parties can converse as desired.

It will be assumed now that the conversation has been successfully completed: and it therefore becomes the duty of the operator to collect the coin or coins which have been deposited in the paystation mechanism bythe subscriber at substation A. In order to collect the coins, the operator actuates the collect key which is associated with outgoing toll service trunk in use. By this operation a circuit is completed for the relay 26, which upon energizing disconnects the exchange battery from the control circuit extending on conductors 66 and 79 to the line relay 104;v

of the repeater D, and substitutes therefor the high voltage battery B1. It is noted that this battery has its negative pole grounded. When the battery `B1 is inserted in the control circuit the How of current therein is considerably augmented, and the marginal relay 109 at the repeater l), which heretofore has remained unoperatlve, is now energized.

Upon attracting its armature 136, relay 109 4 completes circuits for the polarizing windings of the electro-polarized relays 106 and 107, and at the same time, at its armature 137, removes the short circuit around the lower vwindings of these two relays, with the result that the said lower windings are inserted in the control circuit in series with relays 109 andl 104. The upper polarizing windings of'rclays 106 and 107, and the lower windings of these relays, are so wound as reof relay 105. Since relay 105 is not deenergized at this time these latter operations are of no importance justnow. Returning to the electro polarized relay 106 in its operated position this relay breaks the lower conductor of the talking circuit at its armature 131 and at the working contact of this armature connects the high voltage battery B3 with the lower line conductor 145. Battery B3 is similar to battery B1, and in case the repeater andv to'll board are in the same exchange, it may be the Salliel battery. Current now flows from the battery B3 through the right hand winding of relay 115, to the lower line conductor 145, whence the circuit may be traced by way of armature 163 and its working contact, wiper 173, bank contact 177, line conductor 181, working contact of armature 229 andthe said armature, working contact of armature 247 and the said armature, wiper 272, bank contact 275, conductor 321 o f the line of substation A, and

' the winding of the polarized magnet of the.

paystation mechanism` to ground. Responsive'to'the flow of current in the above circuit, the polarized magnet is operated in the proper direction to collect whatever coins may have been deposited, at the same time y disconnecting itself'lir'omy the line circuit. At

repeater `D thelfrelay 115 whose right hand winding'is inl iseries with thebattery B3, is energized and vconnects the low resistance -199in multiple with resistance 112. Whenever relay-26 or relay 27 ,`Fig. 1, is energized the -u per ltalking circuit conductor is connecte by'wayof thel marginal relay 28 to ground.,` Ai circuit may now be traced for this relay28 which extends from its grounded terminal through its winding and by way :of armature31 and its working contact, conductor 61, wiper 70..rv bank contact 74, conductor 78, upper left hand winding of repeating coil R, and the resistances 112 and 199 in parallel to battery. The current flow over the above circuit isY sutlicient to energize relay 28, which thereupon closes the circuit of the collect and refund supervisory lamp,

L2. The lighting of lamp L2 at this time indicates to the operator that one or'more coins were actually deposited and are being collected.

If no coins had been deposited, when the operator actuated her key and connected battery Bs to the line of substitution A, there now restore her collect key momentarily, thus permitting all the circuits having to do with the collection of the coin to restore to their normal osition. The operator will now operateA er collect key once more momentarily in order to make sure that the coin has been collected. If so, the lamp L2 will not be lighted this time, and being sure by this that the deposited coins have been properly collected, the operator will then pull down the connection.

When the plug is removed from jack J all the automatic switching apparatus involved in the connection is released. There is nothing especially new in the releasing operations, so they will only be very briefly described. Upon the removal of the plug from the jack J relays 20 and 21 are deenergized. Relay 21 breaks the holding circuit extending to the toll selector E which is restored to normal through the medium of release magnet 55 upon the deenergization of the switching relay 50. Relay 20, upon deenergizing, breaks the control circuit extending to the line relay 104 of the repeater D, whereupon relays 104 and105 are deenergized. Relay 105 breaks the holding circuit extending to thc toll second selector F which is restored to normal position by its release kmagnet 155 following the deenergization of switching relay 150. The line relay 104 breaks the control circuit extending to the line relay 201 of the connector H and the said relay 201 and relay 202 are therefore deenergized. The latter relay closes the circuit of release magnet 211 which operates in the usual manner to restore the connector H to normal, whereupon all the automatic equipment will havev been released and made ready. for use in subsequent calls.

It will not be necessary to describe in full detail the manner in which the toll operator can refunddeposited coins instead of collect them, as the refunding operation is similar to the collecting operation throughout, except that high voltage batteries having their positive poles rounded Aare used. Thus, as suming that tie previously described connection is set up, and the operator desires to refund the deposited coin, she will operate her refund key. Relay 27 is therefore energized and connects battery B2 in the control circuit extending to the repeater D. The operations at the repeater are the same asbefore described except that since a battery of opposite polarity is now included inthe circuit, the electro-polarized relay 107 will be operated instead of relay 106. As a result, battery B is connected to the subscrbersline rather than battery B3, andthe polarized magnet at the substationis operated in the proper direction to refund the deposited coin. The lamp L2 operates during the refunding operation in the same manner as it does when the` coins are being collected. i

Thereremains one other feature which will now be considered, when it is believed the explanation will have been completed. This feature has to do with an auxiliary coin collecting arrangement which has the function of collecting any deposited coins in case the operator should forget or neglect to collect them. As has been explained before, the operator is supposed to either collect or refund whatever coins have been deposited before she releases the connection but she may forget to do so some times. In order to take care of this contingency, means is provided in the repeater D which is effective during the release of a successful connection to connect the battery B3 with the connected subscribers line and thereby collect any coins which remain undisposed of. This automatic collecting operation only takes place in case a connection has been established which has been answered; in other words, if the local subscriber connected with over the toll service trunks does not answer his telephone, the automatic collect mechanism is not required and is not operated. Let it be assumed that the previously described connection is in the process of being released and that the operator has not collected the deposited coins. Sincethe subscriber at substation A has answered his telephone relay 103 will have been energized when the battery feed relay 100 was operated, being locked to the grounded conductor 144 by way of armature 134 of relay 108.

Now when the relays 104 and 105 of the repeater D are deenergized during the releasing operation circuits are completed by way of armatures 123 and 125 of relay 103 for the relays 110 and 108 respectively. Relay 110 maintains ground on conductor 144 to prevent the release of the toll second sef lector F at its armature140, and at its armature 139 holds the circuit of relay 207 of Jf'thef connector closedsin order toI prevent the d 'eenergization of thering cut ol relay 2 05 .forggxthetime being; while rela 103 mamjtalnsgthe opera-ting` circuit loft e connector lo duet-its' armature 122 in order to relthe",connector from releasing. Re ays f v `,Il )l-land i110 together therefore serve to u maintain theconnecton intact while the relay 108 kis operating to perform the collectr` ing operation. This is done at its armature l135 which serves to connect battery 'B3 to conductor 145 the same as in the case where the electro-polarized relay 106 was energized.

iiBelay 108 also breaks the locking circuitof `relay 103 at its armature 134. Upon deenergizing, relay 103 breaks the circuit of relays 108 and 110. When relays 103 and. 110 .deener ize the release of the connection, which as been suspended, is continued and the remaining apparatus is restored to normal as previously described.

lHaving described my invention what I consider to be new and desire to have protected by Letters Patent will be pointed out in the appended claims.

What I claim as my invention is:

1. In a telephone system, subscribers lines of two classes, the lines of one class only being equipped with paystation mechanism, toll lines, a toll service trunking system comprisin selector and connector switches controlle by an operator for connecting a toll line with a subscribers line of either class, and `signalling means effective to transmit a signal over the established connection through said switches for automatically advising the operator of the class to which any connected line belongs. f

2'. In a telephone system, subscribers lines of two-classes, the lines of one class only being equipped with paystation mechanism, tolllines, a toll service trunking system comprisin selector and connector switches controlle by an operator for connecting a toll line with a subscribers line of either class, and means for transmitting a distinctive audible tone to the o erator over the established connection t rough said switches whenever she connects with a subscribers line belonging to the paystation class.

3. In a telephone system, subscribers lines of two classes including, respectively, ilat' rate and paystation lines, a toll operators position, a toll service trunking system comprising selector and connector switches for exten mg a talking connection from the operators position to a subscribers line of either class, signalling means for automatically advismg the o erator of the class to which any connected 'ne belongs and a class signalling circuit established automatically responsive to the setting up of said talking connection.

4. In a telephone system, subscribers lines `rate and paystation lines, a toll operators position, a toll service trunking system comprisin selector and connector switches for exten lng .a talking connection from the operators position to a subscribers line of either class means for transmitting a, distinctive audible tone to the operator whenevershe connects with a subscribers line belonging tothe paystation class, and circuits over which the tone is transmitted established automatically-responsive to the setting up of said talking connection.

5. In a telephone system a toll operators cord circuit, subscribers ines, a series of automatic switches selectively controllable :from said cord circuit to extend a connection' to a called one of said lines, control circuits extending between said syvitches over which the control is exercised, said circuits beig separate from the talking conductors, a supervisory lamp in said cord circuit, and means for ashing said lamp in case the called line is busy when it is attempted to connect therewith.

6. In a telephone system, a toll operators cord circuit, subscribers lines, means including an'automatic connector switch for extending a connection to a called one of said lines, means in said connector for preventing the completion of such connection if the called line is busy, means for automatically compjleting the connection when the called line ecomes idle, a supervisory lamp in said cord circuit, and means for flashing said lam while the said connector is waiting on the usy line'.

7 In atelephone system, a toll operators cord circuit, subscribers lines, means including an automatic connector switch for eX- tending a connection to a called one of said lines, means in said connector for preventing the completion of such connection if the called line is busy, means for automatically com leting the connection when the called line ecomes idle, a supervisory lamp in said 11o cord circuit, means for flashing said lamp while the said connector is waiting on the busy-line, and means for li hting said lamp continuously when the busy ine becomes idle and the connection thereto is completed.

8. In a telephone s stem, a toll line, a subscribers line, means or connecting said lines comprising a cord circuit and a toll service trunking s stem including selector switches and a fina connector switch, means in said 12o connector for preventing the completion of such connection if the said subscrlbers line is busy, means for automaticall completing the connectm -when the busy ine becomes idle, a supervisory lam in said cord circuit, and means for intermlttentlyv flashing said lam" while the said connector is waiting on t e busy line.

9. In a telephone system, a toll line, a sub- Scribers line, means. for connecting said 13o lines comprising a cord vcircuit and a toll service trunkin s stem including selector switches and a nallconnector switch, means in said connector for preventing the completion of such connection if the said subscribers line is busy, means for automatically completingthe connection. when the busy line becomes idle, a supervisory lamp tently flashing said lam while the said connector is waiting on the usy line, and means for stopping the flashing operationwhen the busy line becomesidle and connection thereto is completed. U

10. In a telephone system comprising a local trunking system for use by local subscribers and a toll service trunking system for use by toll operators, a final connector 'switch .common to both trunking systems, means for operatin said connector to complete a toll connection or a local connection to a called line, automatic ringing equipment automatically started for signalling called lines in the local trunking type of connection, and manually started in the toll trunking type of connection and a ring cut-off relay in said connector used in either type of connection to disconnect said ringing equipment when the called party answers.

11. In a telephone system com rising a local' trunking system for use by ocal subscribers and a toll service trunking system for use by toll operators, a final connector switch common to both trunking systems, means for operating said connector to coinplete a toll connection or a local connection to a called line, automatic ringing equipment normally connected to automatically ring an called line connected with in either type o connection, a ring cut-off relay in said connector, and means for energizing said relay and locking the same electrically while the connector is being operated to complete a toll connection, means for then breaking the locking circuit of said relay any` time after the called line has ,beenV connected with to start the automatic ringing while permitting said relay to remain deenergized to start the automatic ringing at once when the connector is operated to complete a local connection.

12. In a telephone system com rising a local trunking system for use b Focal subscribers and a toll service trun ing'system for use by toll operators, a final connector switch common to both trunking systems, means for operating said connector to complete a toll connection or a local connection to a called line, automatic ringing equipment normally connected to automatically ring any called line connected with in either type of connection, a ring cut-oil relay in said connector, means for energizin said relay and locking the same electrical y while the connector is being operated to complete a toll connection while permitting said relay to remain deenergized to start the automatic rin ing at once when the connector is operated to com lete a local connection, and means broug it into use during a toll connection for unlocking said relay under operator control to start the automatic ringing. in said cord circuit, means for intermitf 13. In a telephone system com rising a local trunking system for use by ocal subscribers and a toll service trunkingv system for use by toll operators, a final connector switch common to both trunking systems, means for operating said connector to complete a toll connection or a local connection to a called line, automatic ringing equipment normally connected to automatically ring any called line connected with in either type of connection, a ring cut-oil' relay in said connector, means for energizing said relay and locking the same electrically while the connector is being operated to complete a toll connection while permitting said relay to remain decnergized to start lthe automatic ringing at once when the connector is operate( to complete la local connection, means brought into use during a toll connection for unlocking said relay under operator control to start the automatic ringing, and a circuit effective when a called line is being signalled in either type of connection for energizing `said cut oi' relay to stop the ringing when the called man answers.

14. In a telephone system, a subscrbers line, an operators position, means including an automatic connector switch whereby the opeiator can extend a connection to said line, automatic ringing equipmentor intermittently signalling called lines, a ring cut-ofi' relay in said connector for disconnecting said ringing equipment, means for energizing said relay and locking the same electrically during the operation of said connector, and means controlled by the operator thereafter for unlocking said relayv to connect said ringing equipment with the connected line.

15. In a telephone system, a` subscribers line, an operators position, means including an automatic connector switch whereby the operator can extend a connection to said line, automatic ringing equipment for intermittently signallingA called lines, a ring cut-off relay in said connector for disconnecting said ringing equipment, means for energizing said relay and locking the saine electrically during the operation of said connector, means controlled by the operator thereafter for unlocking said relay to connect said ringing equipment with the connected line, and a circuit for energizingV said ring cut-oil relay to again disconnect said ringing equipment when the subscriber on said line removes his receiver.

laol 1 16. In a telephone system, a subscribers line, an operators position, means including an automatic rconnector switch whereby the operator can extend a connection to said line, ringing equipment, a. ring cut-ofi' relay in said connector for disconnecting said 5. ringing equipment, means for energizing said relay and locking the same electrically during the operation of said connector, and means controlled by the operator thereafter for unlocking said relay to connect s ald ringing equipment with the connectedllne.

17. In a telephone system, a subscrlbers line, an operators position, means including an automatic connector switch whereby the operator 4can extend a connection to sald line, ringing equipment, a ring cut-off r e lay in said connector for disconnectlngsald ringing equipment, means for energlzlng said relay and locking the same electrically during the operation of said connector, means controlled by the operator thereafter for unlocking said relay to connect said ringing equipment with the connected line, and a circuit for energizing said ring cutoff relay to again disconnect said ringing equipment when the subscriber on said line removes his receiver.

18. In a telephone system, a trunk line terminating in an automatic switch, means for operating said switch to connect said trunk line with a called subscribers line, means for breaking the connection so estab- -lished and for connecting a source of ringsource of ringing current to the said line,

and a low capacity condenser connected around said break to give the operator an audible signal while the ringing operation is taking place.

20. In a telephone system comprising a local trunking system for use by local subscribers and a toll service trunking system for use by' toll operators, a final connector switch common to both systems, means for operating said connector to complete a toll connection or a local connection to a called line, means for breaking any connection so'l established, and for connecting a sourceof ringing current to the called line, and a low capacity condenser connected around said break to give an audible signal to the calling operator or to the calling local subscriber, as the case may be.

21. In a telephone system, subscribers lines, toll lines, means for connecting a toll line with a subscribers line comprising an operators cord circuit and a toll service -trunking system including in serial relation a first selector, a repeater, a second'selector,

and a connector, separate circuits extending from the said repeater to the secondselector and to'the connector for controlling'the re- 22. In a telephone system, subscribersl lines, toll lines, means for connecting a toll line with a subsc'ribers line comprising an operators cord circuit and `a toll service trunking system including in serial relation a first selector, a repeater, a second selector, and a connector, trunk lines included in said trunking system there being a trunk line extending to each of said switches and to said repeater, means in the trunk line extending to said first selector for controlling the release thereof independent of the trunk line extending to said repeater, and means in the repeater for controlling the release of each of the other switches, after theconnection has been established, over a conductor of the trunk line extending thereto.

" 23. In a telephone system, subscribers lines, toll lines, means for connecting a toll line with a subscribers line comprising an operators cord circuit and a toll service trunking system including in serial relation a first selector, a repeater, a second selector, and a connector, trunk lines included in said trunking system there being a trunk line extending to each of Said switches and to said repeater, means for controlling the release of each switch in the connection by means of a separate circuit including a conductor of its associated trunk line, and individual release relays controlled over said circuits, respectively, for controlling the release magnets of saidf switches.`

24. In a telephone system, subscribers lines, toll lines, means for connecting a toll line with a subscribers line comprising an operators cord circuit and a toll service trunking system including in serial relation a first selector, a repeater, a second selector, and a connector, trunk lines included in said trunking system there being a trunk line extending to each of said switches and to said repeater, a relay individual to the trunk line extending to said first selector for transmitting impulses to said first selector, a line relay in said first selector responsive to said impulses to control the operating magnet of said first selectorto operate the same, means for extending the impulse transmitting'circuit to said repeater after the first selector has been operated, said first relay operable thereafter to transmit series of impulses to said repeater over its associated trunk line, means in said repeater for repeating such impulses to said second selector and connector over their associated trunk lines, and individual line relays and-operating magnets responsive to the repeated impulses to operate said second selector and said connector. U

25. In a telephone system, .a connector switch, automaticminging equipment associated with said connector for signalling called lines, a ring cut off relay in said connector for disconnecting said ringing equipment, means for operating said connector in two directive movements to establish connection with a called line, means for energizin said relay before the called line is connecte with, a locking circuit for holding said relay energized to prevent the signalling of the called line when the `connection is completed, and means for subsequently unlocking said relay to start the signalling operation.

26. In a telephone system, a connector switch, automatic ringing equipment associated with said connectoifor signalling called lines, a ring cut off relay in saidconnector for disconnecting said rin 'ng equip ment, means for operating sai connector in two directive movements to establish connection with a called line, means for energizing said relay before the called line is connected with, a locking circuit for holding said relay energized to prevent the signalling of the called line when the connection is completed, means for subsequently unlocking said relay to start the signalling operation, and means for again energizing and locking said relay when the subscribe on the called line answers the call.

y27. In a telephone system, means including a train of automatic switches for extending a connection to a called subscribers line, ringing equipment associated with the final switch of said train, a ring cut off relay in said final switch for disconnecting said ringing equipment, means for energizing and locking said rela before the said connection is completed, an means for unlocking said relay to start signalling the called line at any desired time thereafter.

28. In a telephone system, means including a train of automatic switches f or extending a connection to a called subscrlbers line,

ringing equipment associated with the final' switch of said train, a ring cut off relayin said final switch for disconnecting said ringin equipment, means for energizing and loc ing said relay before the *said connection is completed, means for unlockin said relay toy start signalling the called line at' either of two paths, automatic ringingv equi ment in said connector for intermittent y transmitting signalling current out over the called line irrespective of the path over which the connector is operated, a ring cutoff relay in said connector permitting ringing current to be automatically applied to the line called when the line is seized if the connector has been seized over one path, means for operating and later restoring said relay to delay the transmission of ringing taking place if the connector has been seized via the other path, and a circuit including the called line for operating the said relay to cut off the ring when the called subscriber responds irrespectiveof the path over which .the connection has been extended.

30. In a telephone system, a combination toll and regular connector and means for seizing and o rating it to complete toll or local connections to called lines, automatic ringing equipment in said connector for transmitting ringing current to any line connected with irrespective of the origin of the call, a ring cut-off relay in said connector, circuits for energizing and locking said relay energized prior to the seizure of the desired line when the connector is used in a toll call, operator controlled means for thereafter unlocking said relay to cause the automatic transmission of ringing current to the called line, and a circuit for energizing said relay to cut-ofi' the ring com leted by the response of the called subscriber irrespective of the origin of the call.

In witness whereof, I hereunto subscribe my`name this 19th day of January A. D., 1922.

JOHN WICKS. 

